U.S. patent number 6,357,649 [Application Number 09/532,195] was granted by the patent office on 2002-03-19 for method and apparatus for automatically soldering a lead wire to a solar battery.
This patent grant is currently assigned to Kaneka Corporation. Invention is credited to Akimine Hayashi, Masataka Kondo, Eiji Kuribe, Toshihide Okatsu.
United States Patent |
6,357,649 |
Okatsu , et al. |
March 19, 2002 |
Method and apparatus for automatically soldering a lead wire to a
solar battery
Abstract
A plurality of solder bumps are arranged in a row at regular
pitch in a lead wire soldering region of a solar battery. A
soldering apparatus for soldering a lead wire to the lead wire
soldering region via the solder bumps comprises a lead wire feeding
section for feeding out the lead wire. An end of the lead wire in
the lead wire feeding section is chucked and the lead wire is laid
over all length of the row of solder bumps. The soldering apparatus
further comprises a soldering unit for soldering the lead wire onto
the solder bump. The soldering unit has a lead wire holding member
for holding the lead wire on a solder bump and a soldering iron.
The soldering apparatus repeats an operation for welding the lead
wire to the solder bump by means of the soldering iron, while the
lead wire is held by the lead wire holding member.
Inventors: |
Okatsu; Toshihide (Osaka,
JP), Kondo; Masataka (Kobe, JP), Hayashi;
Akimine (Kobe, JP), Kuribe; Eiji (Osaka,
JP) |
Assignee: |
Kaneka Corporation (Osaka,
JP)
|
Family
ID: |
27530619 |
Appl.
No.: |
09/532,195 |
Filed: |
March 22, 2000 |
Foreign Application Priority Data
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Sep 29, 1999 [JP] |
|
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11-276360 |
Oct 14, 1999 [JP] |
|
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11-292730 |
Oct 27, 1999 [JP] |
|
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11-305533 |
Nov 2, 1999 [JP] |
|
|
11-312399 |
Dec 16, 1999 [JP] |
|
|
11-357400 |
|
Current U.S.
Class: |
228/179.1;
228/1.1; 228/180.5; 228/51 |
Current CPC
Class: |
B23K
1/06 (20130101); B23K 3/0615 (20130101); H01L
21/67138 (20130101); H01L 31/046 (20141201); H01L
31/0201 (20130101); H01L 31/188 (20130101); H01R
43/02 (20130101); Y02E 10/50 (20130101); B23K
2101/42 (20180801); H01L 2924/0002 (20130101); H01L
2924/0002 (20130101); H01L 2924/00 (20130101) |
Current International
Class: |
H01L
21/00 (20060101); B23K 031/00 (); B23K 031/02 ();
B23K 005/20 () |
Field of
Search: |
;228/179.1,180.5,1.1,51,903,904 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
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07-204838 |
|
Aug 1995 |
|
JP |
|
09-083001 |
|
Mar 1997 |
|
JP |
|
08340176 |
|
May 1997 |
|
JP |
|
09-135035 |
|
May 1997 |
|
JP |
|
09135035 |
|
May 1997 |
|
JP |
|
09-295133 |
|
Nov 1997 |
|
JP |
|
09-326497 |
|
Dec 1997 |
|
JP |
|
Primary Examiner: Dunn; Tom
Assistant Examiner: Edmondson; L.
Attorney, Agent or Firm: Hogan & Hartson, L.L.P.
Claims
What is claimed is:
1. A method for automatically soldering a lead wire to a solar
battery via a plurality of solder bumps formed in a row at regular
pitch in a lead wire soldering region of the solar battery, said
method comprising:
a first step for feeding the lead wire from a lead wire feeding
section for feeding out the lead wire to lay the lead wire over all
length of the row of solder bumps;
a second step after the first step for repeating an operation for
holding the lead wire on the solder bump by a soldering unit, an
operation for welding the lead wire to the solder bump and an
operation for releasing the holding of the lead wire, thereby
successively soldering the lead wire from one end to another to the
solder bumps; and
a third step for cutting the lead wire into a soldered lead wire
and an unsoldered lead wire at a position near the lead wire
feeding section.
2. A method according to claim 1, wherein two soldering units are
arranged along a direction of the row of solder bumps, and operated
alternately or simultaneously to solder the lead wire to the solder
bumps.
3. A mechanism for automatically soldering a lead wire to a solar
battery via a plurality of solder bumps formed in a row at regular
pitch in a lead wire soldering region of the solar battery, said
mechanism comprising:
a lead wire feeding section for feeding the lead wire;
a lead wire chuck mechanism for chucking an end of the lead wire in
the lead wire feeding section to feed out the lead wire and laying
the lead wire over all length of the row of solder bumps;
a soldering unit, having a lead holding member for holding the lead
wire on the solder bump while the lead wire is laid over all length
of the row of solder bumps, and a soldering iron, for repeating an
operation for welding the lead wire to the solder bump by means of
the soldering iron, while holding the lead wire on the solder bump
by means of the lead holding member, thereby successively soldering
the lead wire from one end to another to the solder bumps;
a torque control roller for maintaining the tension on the lead
wire substantially constant while the lead wire is soldered to the
solder bumps and for preventing the lead wire from being wrinkled
or cut during soldering; and
a cutter mechanism for cutting the lead wire into a soldered lead
wire and an unsoldered lead wire at a position near the lead wire
feeding section.
4. A mechanism according to claim 3, wherein two soldering units
are arranged along a direction of the row of solder bumps, and
operated alternately or simultaneously to solder the lead wire to
the solder bumps.
5. A mechanism according to claim 4, wherein each of the two
soldering units comprises a soldering iron, and a distance between
the soldering irons coincides with the pitch of the solder
bumps.
6. A mechanism according to claim 3, wherein a plurality of lead
wire feeding sections and a plurality of solder units are provided
in accordance with lead wire soldering regions of the solar
battery, and operated simultaneously.
7. A mechanism according to claim 3, wherein the lead wire feeding
section has a bobbin around which the lead wire is wound.
8. A mechanism according to claim 3, wherein the soldering unit is
supported by a movable base movable along a guide rail and
stepwisely moved along the lead wire soldering region of the solar
battery.
9. A mechanism according to claim 3, wherein the soldering unit has
a lead holding member for holding the lead wire on a solder bump
and a soldering iron for soldering the lead wire to the solder
bump.
10. A mechanism according to claim 3, wherein the lead wire chuck
mechanism is movable to and removable from the lead wire soldering
region, and chucks the end of the lead wire in the lead wire
feeding section when it moves to the lead wire soldering
region.
11. A mechanism according to claim 3, wherein the cutter mechanism
is movable to and removable from the lead wire soldering region,
and cuts the lead wire into the soldered lead wire and the
unsoldered lead wire.
12. A mechanism for automatically soldering a lead wire to a solar
battery having a lead wire soldering region, said mechanism
comprising:
a preparatory soldering apparatus, having a bump soldering iron
movable perpendicular to the lead wire soldering region, for
forming a row of solder bumps arranged at regular pitch in the lead
wire soldering region; and
a lead wire soldering apparatus for supplying the lead wire onto
the row of solder bumps on the solar battery, the lead wire
soldering apparatus including:
a soldering iron, having opposing sides, for welding the lead wire
to the solder bumps;
a lead holding member positioned adjacent the soldering iron;
and
a lead holding pin positioned adjacent the soldering iron on the
side of the soldering iron opposite the lead holder member;
wherein the lead holding member, the soldering iron, and the lead
holding pin sequentially contact the lead wire with the lead
holding member contacting the lead wire first, the soldering iron
contacting the lead wire second, and the lead holding pin
contacting the lead wire last while the soldering iron welds the
lead wire to the solder bumps.
13. A mechanism according to claim 12, wherein the lead wire
holding member includes a holding portion, a longitudinal direction
thereof corresponds to a length direction of the lead wire, for
holding the lead wire from above in cooperation with up and down
movement of the lead wire soldering iron.
14. A mechanism according to claim 12, wherein ultrasonic vibration
is applied to the lead wire soldering iron, when a solder bump of a
lead wire with solder bumps is connected to the lead wire soldering
region.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority
from the prior Japanese Patent Applications No. 11-276360, filed
Sep. 29, 1999; No. 11-292730, filed Oct. 14, 1999; No. 11-305533,
filed Oct. 27, 1999; No. 11-312399, filed Nov. 2, 1999; and No.
11-357400, filed Dec. 16, 1999, the entire contents of which are
incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a method and an apparatus for
automatically soldering a lead wire to a solar battery to connect
the lead wire to positive and negative electrodes of a photovoltaic
module for directly converting solar energy to electrical energy
and deriving an output from the photovoltaic module.
A photovoltaic module for directly converting solar energy to
electrical energy has a layered body, in which a transparent
electrode layer, a photovoltaic semiconductor layer and a rear
surface electrode layer are laminated in this order on an
insulating substrate, such as a glass substrate. The layered body
is divided into a plurality of photoelectric converting cells by a
laser scriber or the like. The photovoltaic cells are electrically
connected to one another in series or parallel.
As disclosed in, for example, Jpn. Pat. Appln. KOKAI Publications
Nos. 9-326497, 9-135035 and 9-83001, a photovoltaic module has lead
wire soldering regions at both end portions.
In the lead wire soldering regions, a number of solder bumps
serving as positive and negative electrodes are formed in a row at
regular intervals. Lead wires are connected to the solder bumps, so
that an output of the photovoltaic module can be derived. The lead
wires are connected to a terminal box attached to the rear surface
of the photovoltaic module.
Further, for example, Published Japanese Patent No. 2691685 and
Jpn. Pat. Appln. KOKAI Publication No. 9-295133 disclose an
apparatus for forming solder bumps in lead wire soldering regions
of a photovoltaic module. With the apparatus, bumps are soldered
efficiently and securely by applying ultrasonic vibration to a
soldering iron.
In the lead wire soldering regions of the photovoltaic module,
solder bumps having a spot diameter of about 2 mm are formed in a
row at intervals of about 20 mm and soldered by means of ultrasonic
soldering. Thereafter, lead wires made of solder-plated copper foil
or the like are placed along the row of the solder bumps. The lead
wires are pressed on the solder bumps by a soldering iron, while
the lead wires are heated from above. Thus, the lead wires are
soldered to the solder bumps.
Conventionally, when lead wires are connected to the lead wire
soldering regions on both sides of the photovoltaic module, first,
solder bumps are formed as preliminary solder in the lead soldering
regions, thereafter lead wires made of solder-plated copper foil or
the like are placed along the row of the solder bumps, and the lead
wires are soldered to the solder bumps. These process are performed
by manual works.
Therefore, when the lead wires are arranged along the row of the
solder bumps and the soldering iron is pressed against the lead
wires from above, the lead wires may be shifted or wrinkled. To
solve this problem, weights are hung from the ends of the lead
wires, so that tension is applied to the lead wires by the gravity
of the weights during the soldering process.
However, the manual work of soldering lead wires to solder bumps is
inefficient, requires a number of steps for mass production, and
increases costs. In addition, since the lead wires are soldered
with tension applied to the lead wires by the weights, the lead
wires soldered between solder bumps are strained. Under these
conditions, if the photovoltaic module is mounted on the roof of a
building or the like, the lead wires may be contract when it is
cooled, resulting in damage or removal from the solder bumps.
Further, the lead wires are connected to the lead wire soldering
regions on both sides of the photovoltaic module in the two steps
of: forming preliminary solder bumps in the lead wire soldering
regions; and placing the lead wires made of solder-plated copper
foil or the like along the row of the solder bumps and soldering
the lead wires to the solder bumps. Therefore, attachment of the
lead wires is complicated and inefficient.
In the case of a large-size photovoltaic module, the insulating
substrate has a size of 910 mm.times.455 mm, and solar battery
sub-modules are formed on the substantially overall surface of the
insulating substrate. In the case of a small-size photovoltaic
module which is mounted on roofing tiles, likewise, a transparent
electrode layer, a photovoltaic semiconductor layer and a rear
surface electrode layer are laminated in this order on an
insulating substrate of the required small size. The layered body
is divided into a plurality of photoelectric converting cells by a
laser scriber or the like. The photoelectric converting cells are
electrically connected to one another in series or parallel.
A photovoltaic module may be produced as follows: a plurality of
solar battery sub-modules are formed with dividing regions
interposed therebetween on an insulating substrate; and thereafter
the insulating substrate is cut at the dividing regions, so that a
plurality of photovoltaic modules can be formed.
Then, belt-shaped lead wires made of solder-plated copper foil or
the like are soldered to positive and negative electrodes of each
solar battery sub-module. The ends of the lead wires are connected
to the terminal box attached to the rear surface of the
photovoltaic module in order to derive an output.
Conventionally, in the case of a small-size solar battery, solar
battery sub-modules are formed on an insulating substrate of that
size in the same manner as in the case of a normal size substrate.
When producing so-called multiple photovoltaic modules after
forming a plurality of solar battery sub-modules on the insulating
substrate, the insulating substrate is cut at the dividing regions
to form a plurality of photovoltaic modules and the lead wires are
connected to the lead wire soldering regions on both sides of each
photovoltaic module. In other words, the solder bumps are first
formed by means of a bump soldering iron in the lead wire soldering
regions on both sides of the divided photovoltaic module, and
thereafter the lead wires are soldered to the solder bumps by means
of a lead wire soldering iron.
As described above, when a layered body is formed on a small-size
insulating substrate or scribed by a laser, it is troublesome to
frequently convey the substrate or a film forming apparatus and a
laser scriber. Moreover, an additional jig or carrier, or an
additional work, such as changing of the work pattern for laser
processing, is required to fix or convey the insulating substrate
to the film forming apparatus or the laser scriber. For this
reason, the forming or laser-scribing of a layered body is
inefficient and costly. Furthermore, when the lead wires are
soldered to the lead wire soldering regions on both end portions of
the small-size photovoltaic module, it is troublesome to convey the
battery module to or from a mount table, whether the soldering is
carried out by hands or an automatic soldering apparatus. Further,
since the soldering cannot be carried out continuously, the work is
insufficient, resulting in an increase in costs.
To guide an output from the photovoltaic module to the terminal box
mounted on the rear surface of the module, as disclosed in Jpn.
Pat. Appln. KOKAI Publication No. 9-326497, lead wires connected to
the terminal box are soldered to positive and negative electrodes
formed on both ends of the photovoltaic module. The soldering is
carried out in the state where an electrode is brought close to or
overlap an end portion of the lead wire, so that the solder is
deposited across the electrode and the lead wire. Likewise,
according to the conventional art, when the direction of a wire is
to be changed in the middle of a conducting path from the electrode
to the terminal box, first and second lead wires are individually
prepared, the end portions of the lead wires are caused to
intersect at right angles, and solder is deposited at the
intersection. Thus, the direction of the conducting path is
changed.
However, according to the aforementioned conventional structure,
the electrode and the lead wire to be soldered are merely brought
close to or overlap each other, and are not bounded to each other.
Therefore, when they are soldered, the relative position
therebetween is liable to be deviated and. Since they must be
soldered taking account of this matter, the soldering workability
is low. In addition, the reliability of the soldering
interconnection may be lowered due to the positional deviation.
Under the circumstances, it is desired to increase the workability
and the reliability of the soldering in order to improve the
quality of the photovoltaic modules.
BRIEF SUMMARY OF THE INVENTION
An object of the present invention is to provide a method and an
apparatus for soldering a lead wire to a solar battery, which can
automatically connect lead wires to a row of solder bumps formed in
a lead wire soldering region of a solar battery, so that the
working efficiency can be improved.
According to the present invention, a lead wire is fed out from a
lead wire feeding section located at an end portion of a row of
solder bumps, and laid over all length of the row. Thereafter, the
lead wire is held on the solder bump, while the lead wire is welded
to the solder bump, beginning with the top end of the lead wire.
The above operation and an operation of releasing the lead wire are
repeated. Then, the lead wire, from the top end toward the rear
end, is successively soldered to the solder bumps. Thus, the lead
wire can be soldered to the solder bumps at high speed, thereby
improving the working efficiency. In addition, the tension of the
lead wire is kept substantially constant, while the lead wire is
soldered to the solder bumps. Therefore, the lead wire is prevented
from being wrinkled or cut, resulting in the advantage that an even
thin and brittle lead wire can be soldered reliably.
Additional objects and advantages of the invention will be set
forth in the description which follows, and in part will be obvious
from the description, or may be learned by practice of the
invention. The objects and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
The accompanying drawings, which are incorporated in and constitute
a part of the specification, illustrate presently preferred
embodiments of the invention, and together with the general
description given above and the detailed description of the
preferred embodiments given below, serve to explain the principles
of the invention.
FIG. 1 is a schematic front view of an apparatus for soldering a
lead wire to a solar battery according to a first embodiment of the
present invention;
FIG. 2 is a schematic side view of the apparatus of the first
embodiment as viewed from the direction of the arrow A shown in
FIG. 1;
FIG. 3 is a cross-sectional view of the solar battery of the first
embodiment;
FIG. 4A is a perspective view of the solar battery of the first
embodiment on which solder bumps are formed;
FIG. 4B is an enlarged perspective view of the third embodiment
showing the portion IVB shown in FIG. 4A;
FIG. 5 is a front view of a soldering unit of the first
embodiment;
FIG. 6 is a side view of a lead wire chuck mechanism and a cutter
mechanism of the first embodiment;
FIG. 7 is a diagram showing the first embodiment as viewed from the
direction of the arrow B shown in FIG. 6;
FIG. 8 is a plan view of the first embodiment in which a lead wire
is laid across solder bumps;
FIG. 9 is a plan view of the first embodiment as viewed from the
direction of the arrow C shown in FIG. 8;
FIG. 10 is a schematic front view of an apparatus for soldering a
lead wire to a solar battery according to a second embodiment of
the present invention;
FIG. 11 is a schematic side view of the apparatus for soldering a
lead wire to a solder battery according to the second
embodiment;
FIG. 12 is a side view of a bump soldering iron of the second
embodiment;
FIG. 13A is a front view of a solder supplying mechanism of the
second embodiment;
FIG. 13B is a side view of the solder supplying mechanism of the
second embodiment;
FIG. 14 is front views showing a process of receiving molten solder
and forming a solder bump by means of the bump soldering iron of
the second embodiment;
FIG. 15 is a side view of a lead wire supplying and soldering
mechanism of the second embodiment;
FIG. 16 is a partially enlarged side view of the lead wire
supplying and soldering mechanism of the second embodiment;
FIG. 17 is an enlarged side view of a lead wire soldering portion
of the second embodiment;
FIG. 18A is a perspective view of a third embodiment of the present
invention;
FIG. 18B is an enlarged perspective view of the third embodiment
showing the portion XVIII shown in FIG. 18A;
FIG. 19 is a front view of an apparatus for manufacturing a lead
wire with solder bumps of the third embodiment;
FIG. 20 is a side view of the apparatus for manufacturing a lead
wire with solder bumps of the third embodiment;
FIG. 21A is a front view of a solder supplying mechanism of the
third embodiment;
FIG. 21B is a side view of a solder supplying mechanism of the
third embodiment;
FIG. 22 is a perspective view of a solar battery of the third
embodiment;
FIG. 23 is an enlarged side view of a lead wire soldering portion
of the third embodiment;
FIG. 24A is a perspective view of a fourth embodiment of the
present invention showing a state in which three solar battery
sub-modules are formed on an insulating substrate and thereafter
lead wires are connected to lead wire soldering regions;
FIG. 24B is a perspective view of the fourth embodiment showing a
state in which the lead wire is cut at dividing regions;
FIG. 24C is a perspective view of the fourth embodiment showing a
state in which the insulating substrate is cut at dividing
regions;
FIG. 25 is a cross-sectional view of a photovoltaic module of the
fourth embodiment;
FIG. 26A is a plan view of a glass cutter of the fourth embodiment;
and
FIG. 26B is a diagram showing the fourth embodiment as viewed from
the direction of the arrow E shown in FIG. 26A.
DETAILED DESCRIPTION OF THE INVENTION
A first embodiment of the present invention will be described with
reference to FIGS. 1 to 9.
FIGS. 1 and 2 show a schematic structure of an apparatus for
soldering a lead wire to a solar battery. A mount table 2 is
provided on a base 1. A solar battery 4 (to be detailed later) is
transferred to and mounted on a mount surface 3 of the mount table
2 with its film forming surface facing upward.
The mount surface 3 has a plurality of abutting projections 5 for
positioning the solar battery 4 in X and Y directions. The abutting
projections 5 are retractably projected in the vertical direction.
A pusher 6 for pressing the solar battery 4 against the abutting
projections 5 is formed on the end of the mount surface 3 opposite
to the abutting projections 5. In the state where the solar battery
4 is positioned in the X and Y directions, the abutting projections
5 and the pusher 6 immovably support the solar battery 4, when
soldering is performed.
A pair of frames 8 corresponding to lead wire soldering regions 7
of the solar battery 4 are provided on the mount table 2. The pair
of frames 8 have automatic soldering mechanisms 9 for automatically
soldering lead wires 10 to the lead wire soldering regions 7. Since
the automatic soldering mechanisms 9 have the same structure, one
of them will be described below.
As shown in FIG. 2, the frame 8 is mounted upright over the entire
length of the mount table 2 in the front-to-back direction. A lead
wire feeding section 11 for feeding the lead wire 10 is provided at
an end portion of the frame 8. The lead wire 10, a belt-like
material made of solder-plated copper foil or the like, is wound
around a bobbin 12. The lead wire 10 fed out from the bobbin 12 is
guided to the lead wire soldering region 7 via a torque control
roller 13 for adjusting tension and a plurality of guide rollers
14. The frame 8 has a first guide rail 15 and a second guide rail
16 extending horizontally in all the length in the longitudinal
direction thereof in upper and lower stages. A first movable base
17 is provided on the first guide rail 15 in the upper stage so as
to be movable stepwisely in the longitudinal direction. First and
second soldering units 18 and 19 are mounted adjacent to each other
along the direction of movement on the first movable base 17. A
second movable base 20 is provided on the second guide rail 16 in
the lower stage so as to be movable stepwisely in the longitudinal
direction. A lead wire chuck mechanism 21 for chucking the top end
of the lead wire 10 and a cutter mechanism 22 for cutting the lead
wire 10 are provided on the second movable base 20.
Timing pulleys 23 are provided in both end portions of the first
guide rail 15 in the longitudinal direction. A timing belt 24 is
looped over the timing pulleys 23. One of the timing pulleys 23 is
connected to a first stepping motor 25 rotatable in normal and
reverse directions. An intermediate portion of the timing belt 24
is connected to the first movable base 17. As the timing belt 24
moves, the first and second soldering units 18 and 19 are moved
along the lead wire soldering region 7.
Timing pulleys 26 are provided in both end portions of the second
guide rail 16 along the longitudinal direction. A timing belt 27 is
looped over the timing pulleys 26. One of the timing pulleys 26 is
connected to a second stepping motor 28 rotatable in normal and
reverse directions. An intermediate portion of the timing belt 27
is connected to the second movable base 20. As the timing belt 27
moves, the lead wire chuck mechanism 21 and the cutter mechanism 22
are moved along the lead wire soldering region 7.
The solar battery 4 will now be described. As shown in FIG. 3, the
solar battery 4 comprises a layered body 34 in which a transparent
electrode layer 31, a photovoltaic semiconductor layer 32 and a
rear surface electrode layer 33 are laminated in this order on an
insulating substrate 30, such as a glass substrate. The layered
body 34 is divided into a plurality of photoelectric converting
cells 35, which are electrically connected to one another.
As shown in FIG. 4, the solar battery 4 has the lead wire soldering
regions 7 on its both end portions. Solder bumps 36 are formed in
advance on each lead wire soldering region 7 at regular intervals
to form a row. A lead wire soldering region 7 may be formed in a
central portion of the solar battery 4, as well as in both end
portions.
The first and second soldering units 18 and 19 will be described.
As shown in FIG. 5, the first and second soldering units 18 and 19
have the same structure. Each soldering unit has a unit body 41 in
which an LM guide (linear motion guide) 42 extends in the vertical
direction. An elevating member 43 is supported by the LM guide 42
so as to be movable up and down. The elevating member 43 is
connected to an elevating rod 45 of a servo motor 44 fixed to the
unit body 41, so that it can be moved up and down.
The elevating member 43 is extended downward from the unit body 4.
A supporting plate 46 extending downward is connected to the
elevating member 43. A soldering iron 47 is fixed to the supporting
plate 46 along the vertical direction. A tip 47a of the soldering
iron faces the lead wire soldering region 7 of the solar battery 4
in which the soldering bumps 36 are formed.
An air cylinder 48 is attached to the supporting plate 46, adjacent
to the soldering iron 47, along the vertical direction. A lead wire
holding member 50 is fixed to the top end portion of an elevating
rod 49 of the air cylinder 48. The lead wire holding member 50
serves to hold the lead wire 10 on the solder bump 36 to ensure the
soldering, when the lead wire 10 is welded to the soldering bump
36.
The first and second soldering units 18 and 19 having the above
structure are arranged symmetrically, so that the soldering irons
47 are close to each other. The distance between the tips 47a of
the soldering irons 47 coincides with the pitch of the solder bumps
36 formed in the lead wire soldering region 7.
The lead wire chuck mechanism 21 and the cutter mechanism 22 for
cutting the lead wire 10 will be described below. As shown in FIGS.
6 and 7, a supporting member 53 is mounted on the second movable
base 20. The supporting member 53 can be moved up and down by a
first air cylinder 52 extending in the vertical direction, so as to
approach and remove from the solar battery 4. An air chuck 55 is
mounted on the supporting member 53. The air chuck 55 can approach
and remove from the lead wire soldering region 7 from the side by
means of a second air cylinder 54 extending in the horizontal
direction.
An air slide table 56 is mounted on the second movable base 20 so
as to be movable in the horizontal direction. A third air cylinder
57 extending in the vertical direction is provided at a distal end
of the air slide table 56. The third air cylinder 57 has a slide
rod 58, to which air nippers 59 constituting the cutter mechanism
22 are connected. Therefore, the air nippers can move to and from
the lead wire soldering region 7, so that it can approach the lead
wire soldering region 7, when it is to cut the lead wire 10.
A method for soldering a lead wire by means of the above lead wire
soldering apparatus for a solar battery will be described
below.
The solar battery 4 transferred into the lead wire soldering
apparatus is placed on the mount table 2 with the rear surface
electrode layer 33 directed up. The solar battery 4 has a number of
solder bumps formed in a row at regular intervals in the lead wire
soldering region 7 in each end portion thereof. The automatic
soldering mechanisms 9 face the lead wire soldering regions 7 on
both end portions of the solar battery 4.
First, the lead wire chuck mechanism 21 stands by at a position
near the lead wire feeding section 11. The top end portion of the
lead wire fed from the bobbin 12 of the lead wire feeding section
11 is chucked by the air chuck 55 of the lead wire chuck mechanism
21.
In this state, when the second stepping motor 28 provided at an end
of the second guide rail 16 is driven, the timing belt 27 is caused
to move via the timing pulley 26. The second movable base 20
connected to the timing belt 27 is guided by the second guide rail
16 and moved in the direction of the arrow a (FIG. 2). As the
second movable base 20 is moved, the top end portion of the lead
wire 10 is drawn in the same direction. Thus, the lead wire 10
wound around the bobbin 12 is fed out. The fed out lead wire 10 is
guided over all the length of the row of solder bumps formed in the
lead soldering region 7, as shown in FIGS. 8 and 9.
At this time, since the lead wire 10 is looped on the torque roller
13, it has substantially constant tension. When the lead wire chuck
mechanism 21 reaches the other end of the second guide rail 16,
i.e., the position farthest from the lead wire feeding section 11,
the second stepping motor 28 is stopped.
When the first stepping motor 25 provided at an end of the first
guide rail 15 is driven, the timing belt 24 is caused to move
stepwisely via the timing pulley 23. The first movable base 17
connected to the timing belt 24 is guided by the first guide rail
15 and moved in the direction of the arrow b (FIG. 2). As the first
movable base 17 is moved, the first and second soldering units 18
and 19 are moved stepwisely in the same direction.
The pitch of movement of the first and second soldering units 18
and 19 is set twice the pitch of the solder bumps 36. When the tips
47a of the soldering irons 47 are located just above the solder
bumps 36 with the lead wire 10 interposed therebetween, the first
and second soldering units 18 and 19 are stopped. More
specifically, assuming that ordinal numbers (first, second, third .
. . ) are consecutively assigned to the solder bumps 36 beginning
with the end corresponding to the top end of the lead wire 10
located above the solder bumps, the soldering iron 47 of the first
soldering unit 18 faces the first solder bump 36 and the soldering
iron 47 of the second soldering unit 19 faces the second solder
bump 36.
The first and second soldering units 18 and 19 are operated
alternately. When the elevating member 43 of the first soldering
unit 18 is lowered by driving the servo motor 44, the lead wire
holding member 50 connected to the soldering iron 47 and the air
cylinder 48 is lowered. At this time, the air cylinder 48 is
operated to cause the lead wire holding member 50 to hold that
portion of the lead wire 10, which is near the first solder bump 36
to be soldered, on the first solder bump 36. As a result, the lead
wire 10 is prevented from rising. In this state, the lead wire 10
is welded to the first solder bump 36 by means of the tip 47a of
the soldering iron 47.
When the soldering by the first soldering unit 18 is completed, the
elevating member 43 of the unit 18 is moved up by driving the servo
motor 44, and the lead wire holding member 50 connected to the
soldering iron 47 and the air cylinder 48 is elevated. At the same
time, the elevating member 43 of the second soldering unit 19 is
moved down by driving the servo motor 44. In the same manner as
described above, the air cylinder 48 of the second soldering unit
19 is operated to cause the lead wire holding member 50 to hold
that portion of the lead wire 10, which is near the second solder
bump 36 to be soldered, on the second solder bump 36. As a result,
the lead wire 10 is prevented from rising. In this state, the lead
wire 10 is welded to the second solder bump 36 by means of the tip
47a of the soldering iron 47.
In this manner, the first and second soldering units 18 and 19 are
operated alternately. When the lead wire 10 is completely soldered
to the first and second solder bumps 36, the first and second
soldering units 18 and 19 move twice the pitch of the solder bumps
36. In other words, the soldering iron 47 of the first soldering
unit 18 faces the third solder bump 36 and the soldering iron 47 of
the second soldering unit 19 faces the fourth solder bump 36. In
this state, the first and second soldering units 18 and 19 are
operated alternately to solder the lead wire 10 to the respective
solder bumps 36.
As described above, the first and second soldering units 18 and 19
are moved stepwisely toward the lead wire feeding section 11.
During this movement, the lead wire is welded to the solder bumps
36 in the lead wire soldering region 7. When only the solder bump
36a immediately before the lead wire feeding section 11 remains,
the first and second soldering units 18 and 19 are temporarily
stopped.
At this time, the air chuck 55 of the lead wire chuck mechanism 21
releases the lead wire 10. When the second stepping motor 28 is
driven, the timing belt 27 is moved in the direction opposite to
the direction of the allow a mentioned above, and the lead wire
chuck mechanism 21 and the cutter mechanism 22 move toward the lead
wire feeding section 11 by 1 or 2 pitches.
The lead wire chuck mechanism 21 and the cutter mechanism 22 move
to the lead wire soldering region 7 and chuck a middle portion of
the lead wire outside of the solder bump 36a to the side nearer to
the lead wire feeding section (on the right side of the solder bump
36a in FIG. 2). In this state, the lead wire 10 is cut by the air
nippers 59 of the cutter mechanism 22 near the solder bump 36a.
Thus, the lead wire 10 wound around the bobbin 12 is divided from
the lead wire 10 soldered to the solder bumps 36. At this time, the
second soldering unit 19 is operated again, so that the rear end
portion of the lead wire 10 is welded to the solder bump 36a. As a
result, the lead wire 10 from the top end to the rear end is
soldered to the row of solder bumps 36, thus completing the
soldering of the lead wire 10 to a solar battery 4.
According to the first embodiment as described above, the lead
wires 10 are soldered to the solder bumps 36 formed on the lead
wire soldering regions 7 on both sides of the solar battery 4 by
simultaneously operating the two automatic soldering mechanisms 9.
However, the two automatic soldering mechanisms 9 may be operated
one by one to solder the lead wires 10 one at a time.
Further, in the above embodiment, the first and second soldering
units 18 and 19 are operated alternately to solder the solder bumps
36 one by one. However, the first and second soldering units 18 and
19 may be simultaneously operated to solder two solder bumps 36 at
a time.
As described above, according to the first embodiment, the lead
wire can be soldered to the solder bumps at high speed. As a
result, the soldering workability can be increased. In addition,
the tension of the lead wire is kept substantially constant, while
the lead wire is soldered to the solder bumps. Therefore, the lead
wire is prevented from being wrinkled or cut, resulting in the
advantage that an even thin and brittle lead wire can be soldered
reliably.
FIGS. 10 to 17 show a second embodiment of the present invention.
Since the solar battery has the same structure as that of the first
embodiment, the same reference numeral is used and a description
thereof is omitted.
FIGS. 10 and 11 are schematic views showing an apparatus for
soldering a lead wire to a solar battery. The apparatus has a base
61, on which a first mount table 62 and a second mount table 63 are
arranged side by side on the same plane. Solar batteries 4 are
placed on the first and second mount tables 62 and 63 with their
film forming surfaces facing upward. Each of the first and second
mount tables 62 and 63 has a support portion 65 for immovably
support the solar battery 4 in a soldering process, and a transfer
mechanism 66 for transferring the solar battery 4 to and from the
first or the second mount table 62 or 63.
A gate-like movable frame 67 is mounted on the base 61 so as to
bridge over the first and second mount tables 62 and 63. The
movable frame 67 is moved stepwisely by a driving mechanism (not
shown) in the direction of the arrow c pitch by pitch.
A preparatory soldering apparatus 71 is mounted on the movable
frame 67 to face the first mount table 62, and a lead wire
soldering apparatus 72 is mounted thereon to face the second mount
table 63. As the movable frame 67 moves, the preparatory soldering
apparatus 71 forms solder bumps on the solar battery 4 placed on
the first mount table 62. Simultaneously, the lead wire soldering
apparatus 72 solders the lead wire 10 to the solder bumps 36 of the
solar battery 4 placed on the second mount table 63.
The preparatory soldering apparatus 71 will now be described in
detail. As shown in FIG. 12, the preparatory soldering apparatus 71
has an XY directions driving mechanism 70 attached to the movable
frame 67 so as to face the lead wire soldering regions 7 in both
sides of the solar battery 4. A servo motor 73, serving as a Z
direction driving mechanism, is attached to the XY directions
driving mechanism 70. The servo motor 73 has an elevating rod 74,
to which a bump soldering iron 76 is attached via a bracket 75
along the vertical direction.
The bump soldering iron 76 comprises an ultrasonic vibrator 77 and
an iron 78 incorporating an electric heater (not shown) directly
connected to the ultrasonic vibrator 77. The tip of the iron 78 is
tapered. A camera 79 is provided near the bump soldering iron 76 to
pick up an image of an alignment mark (not shown) formed in a
corner portion of the solar battery 4 placed on the first mount
table 62. The camera 79 is attached to the movable frame 67 via a
bracket 80.
If the bump soldering iron 76 is positioned to the solar battery 4
by pressing the solar battery 4 to a positioning bar without using
a camera or an alignment mark, it is unnecessary to provide a
camera.
As shown in FIGS. 13A and 13B, a solder supplying mechanism 81 is
attached to the movable frame 67 near the bump soldering iron 76.
The solder supplying mechanism 81 has a feeding roller 84 for
stepwisely feeding linear solder 82 from a bobbin 83 on which the
linear solder 82 is wound around. The linear solder 82 is inserted
in a guide pipe 85 bent like an arc such that an opening faces up.
The guide pipe 85 is a tube made of a material having a small
coefficient of friction, for example, Teflon or nylon. A portion of
the guide pipe 85 near an upward opening 86 directed upward is
attached to the movable frame 67 via a holder 87. The linear solder
82 is projected through the upward opening 86 by a fixed
length.
To form solder bumps 36 on the lead wire soldering regions 7 on
both sides of the solar battery 4 by means of the bump soldering
iron 76, the iron 78 of the bump soldering iron 76 is caused to
face the upward opening 86 of the solder supplying mechanism 81 by
driving the XY directions driving mechanism 70 of the preparatory
soldering apparatus 71, as shown in FIG. 14.
When the bump soldering iron 76 is lowered by the servo motor 73,
the tip of the iron 78 is brought into contact with the linear
solder 82 projected through the upward opening 86. The linear
solder 82 is melted by the iron 78 which is heated by the electric
heater.
Then, when the bump soldering iron 76 is raised by the servo motor
73, a molten solder 82a of a fixed amount is adhered to the tip of
the iron 78, so that the molten solder 82a can be supplied to the
solar battery 4 on the first mount table 62. The bump soldering
iron 76 is caused to face the lead wire soldering region 7 of the
solar battery 4 on the mount table 62 by driving the XY directions
driving mechanism 70 of the preparatory soldering apparatus 61.
Then, when the bump soldering iron 76 is lowered by the servo motor
73, the molten solder 82a adhered to the tip of the iron 78 is
brought into contact with the lead wire soldering region 7, thereby
forming a solder bump 36.
At this time, to detect the height of the solar battery 4 in the Z
direction, the tip of the iron 78 is first brought into contact
with the lead wire soldering region 7, to pick out a datum point.
Thereafter, the soldering iron 76 is lifted by the servo motor by a
predetermined length, and forms the solder bump 36 in the lead wire
soldering region 7, while ultrasonic vibration is applied to the
iron 78 by the ultrasonic vibrator 77. The above operation is
repeated as the movable frame 67 is moved stepwisely pitch by pitch
in the direction of the arrow c. As a result, a row of solder bumps
36 are formed on the lead wire soldering region 7.
In the solder supplying mechanism 81, the linear solder 82 is
stepwisely fed by the feeding roller 84 from the bobbin 83, so that
it is projected from the upward opening 86 by a fixed length at a
time. Therefore, a fixed amount of the molten solder 82a is adhered
to the tip of the iron 78 of the bump soldering iron 76.
Accordingly, the solder bumps 36 formed on the lead wire soldering
region 7 have substantially the same size. In addition, since
ultrasonic vibration is applied to the bump soldering iron 76 while
the iron is being pressed against the lead soldering region 7, the
solder bumps 36 can be firmly fixed to the region 7.
The lead wire soldering apparatus 72 will now be described. As
shown in FIGS. 15 to 17, a Y direction driving mechanism 90 is
attached to the movable frame 67 so as to face the lead wire
soldering region 7 of the solar battery 4 on which the solder bumps
36 are formed. A lead wire supplying and soldering mechanism 91 is
attached to the Y direction driving mechanism 90 so as to be
movable up and down via a Z direction driving mechanism (not
shown).
The lead wire supplying and soldering mechanism 91 has an
attachment plate 92 movable up and down. A lead wire supplying
section 93 for supplying the lead wire 10 is mounted on an upper
portion of the attachment plate 92. As in the first embodiment, the
lead wire 10 is made of solder-plated copper foil having a width of
about 2 mm, and wound around a bobbin 94 rotatably supported by the
attachment plate 92.
A vertical guide 95 and an arc guide 96 having a curvature and
continuously connected to the lower end of the vertical guide 95
are arranged under the bobbin 94. Further, a horizontal guide 97 is
continuously connected to the arc guide 96. The lead wire 10 fed
from the bobbin 94, supplied via a guide roller 98, is inserted
into the vertical guide 96, the arc guide 96 and the horizontal
guide 97 in this order, so that it is guided to the solar battery 4
on the second mount table 63.
A lead wire pressing cylinder 99 is attached to the vertical guide
95. The radius of curvature of a curve portion 96a of the arc guide
96 is R40 mm or more, preferably, R60 mm or more. The horizontal
guide 97 has a guide groove 100, which is open downward, i.e.,
toward the solar battery 4.
The vertical guide 95, the arc guide 96 and the horizontal guide 97
are formed of a gap having a width slightly greater than the
thickness of the lead wire 10. At least a portion of the inner
surface of the gap that is brought in contact with the lead wire 10
is coated with, for example, Teflon or nylon, so that the lead wire
10 can be slid, guided and supplied smoothly. The smoothing means
is not limited to the Teflon or nylon coating. Alternatively, the
vertical guide 95, the arc guide 96 and the horizontal guide 97
themselves may be made of Teflon or nylon.
As described above, the horizontal guide 97 has a guide groove 100,
which is open downward, i.e., toward the solar battery 4. The
horizontal guide 97 also has a large hole 101, a long hole 102 and
a small hole 103 bored therethrough toward the guide groove 100.
The long hole 102 is located on the top end side of the horizontal
guide 97 of the large hole 101, and the small hole 103 is located
on the distal end side thereof.
Further, a side plate 104 is formed integral with the attachment
plate 92. A first air cylinder 105 is attached to the side plate
104 in the vertical direction. The first air cylinder 105 has an
elevating rod 106, to which a lead wire soldering iron 108 is
attached via a bracket 107 along the vertical direction.
The lead wire soldering iron 108 comprises an ultrasonic vibrator
109 and an iron 110 incorporating an electric heater (not shown)
directly connected to the ultrasonic vibrator 109. The tip of the
iron 110 is tapered. The iron 110 is positioned to face the large
hole 101 of the horizontal guide 97 and press the upper surface of
the lead wire 10 through the large hole 101. The ultrasonic
vibrator 109 is not necessarily provided.
A bracket 111, having an angle and symmetric with respect to the
axis of the lead wire soldering iron 108, is attached to the side
plate 104. A second air cylinder 112 and a third air cylinder 113
are attached to the bracket 111 at angles on both sides of the lead
wire soldering iron 108. The second air cylinder 112 has an
elevating rod 114, to which a lead wire holding member 116 is
connected by a pin 115. The lead wire holding member 116 is
constituted by a substantially triangular plate having a holding
portion 116a, the longitudinal direction thereof corresponds to the
length direction of the lead wire 10, so that the soldered lead
wire 10 can be held over a wide range. The lead wire holding member
116 holds the upper surface of the lead wire 10 through the long
hole 102 of the horizontal guide 97.
The third air cylinder 113 has an elevating rod 117, to which a
lead wire holding pin 118. The top end portion of the lead wire
holding pin 118 is tapered, and holds the lead wire 10 before
soldered through the small hold 103 of the horizontal guide 97.
The second air cylinder 112, the first air cylinder 105 and the
third air cylinder 113 are sequentially operated in this order.
Thus, the soldered lead wire 10 can be held by means of the lead
wire holding member 116 over a wide range on the solder bumps
formed on the lead wire soldering region 7 of the solar battery 4.
Further, the lead wire 10 is pressed against the solder bump 36 by
the lead wire soldering iron 108, and held on the next solder bump
36 by the lead wire holding pin 118. In this state, the lead wire
10 is soldered to the solder bump 36.
The preparatory soldering apparatus 71 and the lead wire soldering
apparatus 72 including the first and second mount tables 62 and 63
have a dust-proof structure covered by a transparent cover 120.
Therefore, the operator can monitor the operation from the outside
through the cover 120.
A method for automatically soldering a lead wire to a solar battery
will now be described.
A solar battery 4 is transferred into the apparatus for soldering a
lead wire to a solar battery, before solder bumps are formed on a
few lead wire soldering regions 7 on both sides, or both sides and
an intermediate portion therebetween. The solar battery 4 comprises
a layered body 34 in which a transparent electrode layer 31, a
photovoltaic semiconductor layer 32 and a rear surface electrode
layer 33 are laminated in this order on an insulating substrate 30.
The layered body 34 is divided into a plurality of photo-electric
converting cells 35, which are electrically connected to one
another. The solar battery 4 is placed on the first mount table 62
with the rear surface electrode layer 33 facing up.
The solar battery 4 transferred onto the second mount table 63 has
solder bumps 36 formed in rows on the lead wire soldering regions 7
on both sides by means of the preparatory soldering apparatus 71.
It is transferred by the transfer mechanism 66 from the first mount
table 62.
The movable frame 67 is moved stepwisely in the direction of the
arrow c pitch by pitch. The preparatory soldering apparatus 71 and
the lead wire soldering apparatus 72 mounted on the movable frame
67 are operated simultaneously. Thus, solder bumps 36 are formed on
the solar battery placed on the first mount table 62, while the
lead wire 10 is soldered to the solar bumps on the solar battery
placed on the second mount table 63.
When the solar battery 4 is transferred to the first mount table 62
with its rear surface facing up, it is immovably supported by the
support portion 65. Then, the movable frame 67 is moved, bridging
over the first and second mount tables 62 and 63. The camera 79 of
the preparatory soldering apparatus 71 picks up an image of an
alignment mark (not shown) formed on the solar battery 4. Based on
the read signal output from the camera, the XY directions driving
mechanism 70 is operated, so that the bump soldering iron 76 faces
the lead wire soldering region 7 of the solar battery 4.
If the positioning of the bump soldering iron 76 is executed by
pressing the solar battery 4 to a positioning bar without using a
camera or an alignment mark, no camera is provided to the bump
soldering iron. In this case, a reference surface of the solar
battery 4 is pressed against a fixed positioning bar (not shown) by
a movable positioning bar (not shown), thereby setting the solar
battery 4 to a predetermined position. The XY directions driving
mechanism 70 is operated, so that the bump soldering iron 76 faces
the lead wire soldering region 7 of the solar battery 4.
At this time, as shown in FIG. 14, the iron 78 of the bump
soldering iron 76 is caused to first face the upward opening 86 of
the guide pipe. Then, the bump soldering iron 76 is moved down by
the servo motor 73. When the tip of the iron 78 is brought into
contact with the linear solder 82 projected through the upward
opening 86, the linear solder 82 is melted by the iron 78 heated by
the electric heater.
Subsequently, when the bump soldering iron 76 is moved up by the
servo motor 73, a molten solder 82a of a fixed amount is adhered to
the tip of the iron 78. The bump soldering iron 76 is caused to
face the lead wire soldering region 7 of the solar battery 4 on the
first mount table 62 by driving the XY directions driving mechanism
70 of the preparatory soldering apparatus 71. Then, when the bump
soldering iron 76 is lowered by the servo motor 73, the molten
solder 82a adhered to the tip of the iron 78 is brought into
contact with the lead wire soldering region 7, thereby forming a
solder bump 36.
At this time, to detect the height of the solar battery 4 in the Z
direction, the tip of the iron 78 is first brought into contact
with the lead wire soldering region 7, to pick out a datum point.
Thereafter, the soldering iron 76 is lifted by the servo motor 73
by a predetermined length suitable for a predetermined amount of
solder, and forms the solder bump 36 in the lead wire soldering
region 7.
The above operation is repeated as the movable frame 67 is moved
stepwisely pitch by pitch in the direction of the arrow c. As a
result, a row of solder bumps 36 are formed on the lead wire
soldering region 7 at regular intervals, from one end to the other
end of the solar battery 4.
An operation of the lead wire soldering apparatus 72 will be
described. First, the Y direction driving mechanism 90 is operated,
so that the lead wire supplying and soldering mechanism 91 faces
the lead wire soldering regions 7 on both sides of the solar
battery 4, in which solder bumps 36 are formed. At this time, a
camera 79 picks up an image of an alignment mark (not shown) formed
on the solar battery 4, so that the mechanism 91 can be suitably
positioned to the solar battery.
If the solar battery 4 is positioned by pressing the solar battery
4 to the positioning bar without using a camera or an alignment
mark, no camera is provided. In this case, the reference surface of
the solar battery 4 is pressed against the fixed positioning bar
(not shown) by the movable positioning bar (not shown), thereby
setting the solar battery 4 to a predetermined position.
Then, when the lead wire supplying and soldering mechanism 91 is
lowered by the Z directions driving mechanism, the horizontal guide
97 attached to the attachment plate 92 comes close to the lead wire
soldering region 7.
At this time, the lead wire 10 is fed out from the bobbin 94, and
sequentially guided through the vertical guide 95, the arc guide 96
and the horizontal guide 97 in this order. Further, it is guided to
the lead wire soldering region of the solar battery 4 having the
solder bumps 36 through the guide groove 100.
Then, the elevating rod 114 of the second air cylinder 112 is
lowered first, so that a wide range of the lead wire 10 is held on
the solder bumps 36 by the lead wire holding member 116. Secondly,
the elevating rod 106 of the first air cylinder 105 is lowered to
press the lead wire 10 against the solder bump 36 by means of the
lead wire soldering iron 108. Thirdly, the elevating rod 117 of the
third air cylinder 113 is lowered to press the lead wire 10 against
the lead wire soldering region 7.
In this state, when the ultrasonic vibrator 109 of the lead wire
soldering iron 108 is ultrasonically vibrated, ultrasonic vibration
is applied to a pressured contact portion between the lead wire 10
and the solder bump 36 through the iron 110. In addition, the
solder of the lead wire 10 and the solder bump 36 are melted by
heat generated by the electric heater incorporated in the lead wire
soldering iron 108, so that the lead wire 10 is soldered to the
solder bump 36. At this time, ultrasonic vibration is not
necessarily required. Depending on the circumstances, ultrasonic
vibration is not applied.
Upon completion of soldering of the lead wire 10 to one solder bump
36, the first, second and third air cylinders 105, 112 and 113 are
sequentially operated in this order. As a result, the elevating
rods 106, 114 and 117 are moved up. At the same time, the movable
frame 67 is moved by a pitch in the direction of the arrow c, and
the lead wire 10 is soldered to the next solder bump 36. The above
operation is repeated, thereby connecting the lead wire 10 to the
row of solder bumps 36 from one end to the other end of the solar
battery 4.
At this time, a wide range of the soldered portion of the lead wire
10 is held by the plate-like lead wire holding member 116 extending
along the longitudinal direction of the lead wire. The portion of
the lead wire 10, which has not been soldered, is held by the lead
wire holding pin 118. The intermediate portion of the lead wire 10,
between the portions held by the holding member 116 and the holding
pin 118, is soldered to the solder bump 36. Therefore, excessive
tension is not exerted on the lead wire 10, and the lead wire 10 is
not removed from the solder bump 36 due to heat shrinkage of the
soldered lead wire 10.
When the lead wire 10 is completely soldered to the lead wire
soldering region 7 over all the length, it is cut at a
predetermined position. After the lead wire 10 is cut, the solar
battery 4 is transferred out from the second mount table 63 by the
transfer mechanism 66, and another solar battery 4 is transferred
to the second mount table 63 from the first mount table 62.
Thus, processes of forming solder bumps 36 on the solar battery 4
to soldering the lead wire 10 to the solder bumps 36 can be
performed totally automatically. Further, the bump soldering iron
76 and the lead wire soldering iron 108 are controlled to be moved
up and down by the servo motors 73 and the first air cylinder 105
to perform soldering. If one of the two soldering irons has
trouble, the other soldering iron is temporarily stopped
simultaneously. In this case, the soldering irons are stopped at
elevated positions. Therefore, the solar battery 4 can be prevented
from being broken by the soldering irons.
In the second embodiment, the preparatory soldering apparatus and
the lead wire soldering apparatus are mounted on the separate mount
tables. However, they can be mounted on the same mount table, so
that immediately after preparatory solder bumps are formed, a lead
wire can be soldered to the solder bumps. In this case, a
preparatory soldering iron unit and a lead wire soldering iron unit
are set tandem along the direction of movement of the lead
soldering region, so that the lead wire is soldered to the
just-formed preparatory solder bumps.
The above structure is complicated, but advantageous in that the
solar battery is required to be positioned only once.
According to the second embodiment, formation of the solder bumps
on the lead wire soldering regions of the solar battery and
connection of the lead wire to the solder bumps are performed
automatically. Therefore, the working efficiency can be improved.
Further, in association with the downward movement of the lead wire
soldering iron, the soldered lead wire is held by the lead wire
holding member, the longitudinal direction thereof corresponds to
the length direction of the lead wire. Thus, since a wide range of
the soldered lead wire is held, the lead wire is prevented from
being wrinkled or cut, resulting in the advantage that an even thin
and brittle lead wire can be soldered reliably.
Moreover, a material having a small coefficient of friction is used
to form the surface of the lead wire supplying section for guiding
the lead wire to the lead wire soldering region of the solar
battery. Therefore, the inner portion of the lead wire supplying
section is prevented from being clogged with the lead wire or
damaged due to adhesion of solder of the lead wire to that portion.
Accordingly, the lead wire can be supplied smoothly, and
automatically connected to the solder bumps formed in the lead wire
soldering region, resulting in an increase in working
efficiency.
FIGS. 18A, 18B to 21 shows a third embodiment of the present
invention. As shown in FIGS. 18A and 18B, a lead wire 121 with
solder bumps, made of solder-plated copper foil, comprises a
belt-like lead wire 122 having a width of about 2 mm, and solder
bumps 123 having a diameter of, for example, 1-2 mm, soldered to
one side of the lead wire 122 at intervals of, for example, 10
mm.
An apparatus for producing a lead wire with bumps will be described
with reference to FIGS. 19 to 21.
The apparatus includes a base 125 having an upper surface on which
a lead wire guide groove 126 is formed. The groove 126 is slightly
wider than the lead wire 122. A lead wire feeding reel 127 is
connected to the base 125 at an end of the lead wire guide groove
126. The lead wire 122 is wound around the lead wire feeding reel
127.
A lead wire take-up reel 128 is connected to the base 125 at the
other end of the real wire guide groove 126. The lead wire take-up
reel 128 has a rotation shaft 129 to which a pulley 130 is
attached. The pulley 130 works along with a pulley 133 of a motor
132 via a belt 131. The motor 132 rotates stepwisely, so that the
lead wire 122 stepwisely travels along the lead wire guide groove
126.
A bump soldering apparatus 134 is provided on the base 125 located
near the lead wire guide groove 126. The bump soldering apparatus
134 is mounted on a frame 135 via an XY directions driving
mechanism 136. An air cylinder 137, serving as a Z direction
driving mechanism, is connected to the XY directions driving
mechanism 136. The air cylinder 137 has an elevating rod 138, to
which a bump soldering iron 140 is connected via a bracket 139
along the vertical direction.
The bump soldering iron 140 comprises an iron 142 incorporating an
electric heater (not shown). The tip of the iron 142 is tapered. A
solder supplying mechanism 143 is attached to the frame 135 near
the bump soldering iron 140. The solder supplying mechanism 143 has
a bobbin 145, around which a linear ceramic solder 144 is wound,
and a feeding roller 146 for stepwisely feeding out the linear
ceramic solder 144 from the bobbin 145. The linear ceramic solder
144 is inserted in a guide pipe 147 bent like an arc such that an
opening faces up. The guide pipe 147 is a tube made of a material
having a small coefficient of friction, for example, Teflon or
nylon. A portion of the guide pipe 147 near an upward opening 148
directed upward is attached to the frame 135 via a holder 149. The
linear ceramic solder 144 is projected through the upward opening
148 by a fixed length.
An apparatus for forming solder bumps 123 on a side of the lead
wire 122 by means of the bump soldering iron 140 has the same
structure as that of the preparatory soldering apparatus 71 of the
second embodiment shown in FIG. 10. An apparatus for soldering the
lead wire 121 with solder bumps to a solar battery 4 shown in FIG.
22 is the same as the lead wire soldering apparatus 91 of the
second embodiment shown in FIGS. 15 and 16. Therefore, descriptions
of these apparatuses will be omitted.
A function of an apparatus for soldering a lead wire to a solar
battery according to this embodiment will now be described.
A solar battery 4 transferred to the lead wire soldering apparatus
91 is placed on the mount table with the lead wire soldering
regions 7 on both sides thereof facing upward. The lead wire
soldering apparatus 91 is stepwisely moved pitch by pitch, with the
result that the lead wire 121 with solder bumps are soldered to the
lead wire soldering region 7 of the solar battery 4, as shown in
FIG. 23.
More specifically, the lead wire 121 with solder bumps is fed out
from the bobbin 94 and guided to the lead wire soldering region 7
of the solar battery 4. Then, the elevating rod 117 of the third
air cylinder 113 is lowered to press the lead wire 121 with solder
bumps against the lead wire soldering region 7.
In this state, when the ultrasonic vibrator 109 of the lead wire
soldering iron 108 is ultrasonically vibrated, ultrasonic vibration
is applied through the iron 110 to a pressured contact portion
between the lead wire 121 with solder bumps and the lead wire
soldering region 7. In addition, the solder of the lead wire 121
with solder bumps and the solder bump 123 are melted by heat
generated by the electric heater incorporated in the lead wire
soldering iron 108, so that the lead wire 121 with solder bumps is
soldered to the lead wire soldering region 7.
Upon completion of soldering of the lead wire 121 with solder bumps
to one solder bump 123, the first, second and third air cylinders
105, 112 and 113 are sequentially operated in this order. As a
result, the elevating rods 106, 114 and 117 are moved up. At the
same time, the lead wire soldering apparatus 91 is moved by a
pitch, and solders the lead wire 121 to the next solder bump 123.
The above operation is repeated, thereby connecting the lead wire
121 with solder bumps to the lead wire soldering region 7 from one
end to the other end of the solar battery 4.
At this time, a wide range of the soldered portion of the lead wire
121 with solder bumps is held by the plate-like lead wire holding
member 116 extending along the longitudinal direction of the lead
wire 121. The portion of the lead wire 121, which has not been
soldered, is held by the lead wire holding pin 118. The solder bump
in the intermediate portion of the lead wire 121 with solder bumps,
between the portions held by the holding member 116 and the holding
pin 118, is soldered to the lead wire soldering region 7.
Therefore, excessive tension is not exerted on the lead wire 121
with solder bumps, and the lead wire 122 is not removed from the
lead soldering region 7 due to heat shrinkage of the soldered lead
wire 122.
When the lead wire 121 with solder bumps is completely soldered to
the lead wire soldering region 7 over all the length, it is cut at
a predetermined position. After the lead wire 121 with solder bumps
is cut, the solar battery 4 is transferred out from the mount
table, and another solar battery 4 is transferred to the mount
table. Thus, soldering of the lead wire 121 with solder pumps to
the solar battery can be performed totally automatically.
According to the third embodiment, since the lead wire and the
solder bumps are formed integrally into one, the lead wire can be
directly connected to the lead wire soldering region of the solar
battery without forming preparatory solder bumps in advance.
Therefore, the second embodiment has an advantage that the
efficiency of soldering lead wires is further improved.
FIGS. 24A to 26 show a fourth embodiment of the present invention.
This embodiment is a method for producing photovoltaic modules, in
which a plurality of, for example, three solar battery sub-modules
are formed on one insulating substrate, and they are cut at
dividing regions.
As shown in FIG. 24A, three solar battery sub-modules 153a, 153b
and 135c are formed on an insulating substrate 152, and lead wires
155 are connected to lead wire soldering regions 154a and 154b in
both side portions of each of the solar battery sub-modules 153a,
153b and 135c. FIG. 24B shows a state in which the lead wires 155
are cut at dividing regions 156a and 156b. FIG. 24C shows a state
in which the insulating substrate 152 is cut at the dividing
regions 156a and 156b.
Since the solar battery sub-modules 153a, 153b and 135c have the
same structure, one of them will be described. As shown in FIG. 25,
each solar battery sub-module has a layered body 160, in which a
transparent electrode layer 157, a photovoltaic semiconductor layer
158 and a rear surface electrode layer 159 are laminated in this
order on an insulating substrate 152, such as a glass substrate.
The layered body 160 is divided into a plurality of photoelectric
converting cells 161, which are electrically connected to one
another.
A method for producing a photovoltaic module 151 will now be
described with reference to FIGS. 24A to 24C. The insulating
substrate 152 has a size of, for example, 910 mm.times.455 mm, and
the three solar battery sub-modules 153a, 153b and 135c are formed
on the insulating substrate 152. The insulating substrate 152 is
transferred to a lead wire connecting step, in which solder bumps
162 as shown in FIG. 25 are formed on the lead wire soldering
regions 154a and 154b of each of the solar battery sub-modules
153a, 153b and 135c.
Then, a lead wire 155 is continuously laid across the dividing
regions 156a and 156b on a row of solder bumps 162. The lead wire
155 is heated, while it is pressed against a solder bump 162, with
the result that it is connected to the solder bump 162.
The solder bumps 162 may be formed on the lead wire soldering
regions 154a and 154b either automatically or manually by means of
a bump soldering iron. Further, the lead wire 155 may be connected
to the solder bump 162 either manually with a lead wire soldering
iron or automatically by an automatic soldering apparatus.
Alternatively, a lead wire with solder bumps may be used to connect
the lead wire 155 to the lead wire soldering region. In this case,
the step for forming solder bumps on the lead wire soldering region
is omitted.
Thereafter, the lead wire 155 extending across the dividing regions
156a and 156b is cut by a cutter or the like at the dividing
regions 156a and 156b. As a result, the lead wire 155 is cut into
the portions respectively in the solar battery sub-modules 153a,
153b and 153c.
The lead wire 155 is cut such that a cut end portion thereof may
not project from the rear surface electrode layer 159. After the
lead wire 155 is cut, a process of insulating a peripheral region,
a performance test, or a cleaning process may be performed, if
necessary.
Then, the photovoltaic module 151 is taken out from the lead wire
connecting step, and transferred into a substrate dividing step. In
the substrate dividing step, as shown in FIGS. 26A and 26B, the
insulating substrate 152 is cut at the dividing regions 153a and
153b by a glass cutter 163 into a plurality of solar-battery
sub-modules, e.g., the solar battery sub-modules 153a, 153b and
135c.
The glass cutter 163 has a longitudinal reference surface 165 and a
lateral reference surface 166 forming the angle of 90.degree. with
a mount table 164, on which the photovoltaic module 151 is placed.
A frame 167, extending parallel with the longitudinal reference
surface 165, is mounted on the mount table 164 so as to be movable
in parallel with the lateral reference surface.
The frame 167 has an LM guide 168. A cutter head 170 having a
diamond cutter 169 is movably attached to the LM guide 168. The
cutter head 170 is moved manually or by a driving mechanism (not
shown).
The photovoltaic module 151 to be divided is placed on the mount
table 164 with the insulating substrate 152 facing upward. A
longitudinal surface 151a and a lateral surface 151b are
respectively brought into contact with the longitudinal reference
surface 165 and the lateral reference surface 166. As a result, the
photovoltaic module 151 is positioned in X and Y directions. Then,
the frame 176 is moved in the lateral direction to position the
diamond cutter 169 with respect to a parting line L drawn in the
dividing region 156b of the photovoltaic module 151. In this state,
the cutter head 170 is moved along the LM guide 168 in the
direction of the arrow shown in FIGS. 26A and 26B, thereby forming
a mark-off line (groove) in the parting line L with the diamond
cutter 169.
The frame 167 is moved again in the lateral direction to position
the diamond cutter 169 with respect to a parting line L drawn in
the dividing region 156a of the photovoltaic module 151. In this
state, the cutter head 170 is moved along the LM guide 168 in the
direction of the arrow, thereby forming a mark-off line (groove) in
the parting line L with the diamond cutter 169.
Then, the photovoltaic module 151 is lifted up from the mount table
164. Thereafter, pressure force or shock is applied to the
insulating substrate 152, using the parting lines L as fold
fulcrums. As a result, the insulating substrate 152 is cut along
the parting lines L, so that three solar battery sub-modules 153a,
153b and 153c can be obtained.
In general, after glass is cut, a cut side of the glass has an
acute angle. Therefore, a process for removing the acute angle
portion (chamfering) may be required in order to return the side to
the original state of the substrate side. It is possible to cut the
photovoltaic module 151 after output deriving wires are connected
and sealed.
In the fourth embodiment described above, the three solar battery
sub-modules 153a, 153b and 153c are formed on the insulating
substrate 152. However, the number of sub-modules formed on the
insulating substrate 152 is not limited. Further, photovoltaic
modules of different sizes may be formed on the insulating
substrate 152.
According to the fourth embodiment, even when a photovoltaic module
of a small size is produced, formation of a transparent electrode
layer, a photovoltaic semiconductor layer and a rear surface
electrode layer and laser scribing of a layered body comprising
these layers are carried out in the same manner as in the case of
producing a standard large-size photovoltaic module. In addition,
since the lead wires can be continuously connected to the lead wire
soldering regions, the working efficiency can be improved.
Additional advantages and modifications will readily occur to those
skilled in the art. Therefore, the invention in its broader aspects
is not limited to the specific details and representative
embodiments shown and described herein. Accordingly, various
modifications may be made without departing from the spirit or
scope of the general inventive concept as defined by the appended
claims and their equivalents.
* * * * *